The present invention relates to aircraft, and more particularly, to systems and methods for recording and retrieving information about the performance of an aircraft and its crew during flight.
Whenever an aircraft crashes, governmental authorities, aircraft manufacturers and the public have a keen interest in determining the cause of the crash. Commercial aircraft have long employed a flight data recorder (FDR) and a voice data recorder (VDR) to aid in the accident reconstruction and diagnostic process. The FDR records various flight parameters such as engine status, fuel status, airspeed, altitude, attitude and control settings. The VDR typically records the voice communications of the crew members, although it may also pick up other extraneous noise in the cockpit such as an explosion. The FDR and VDR have usually been provided in the form of on-board tape or disk recorders. They are typically packaged in an armored casing, sometimes called a xe2x80x9cblack boxxe2x80x9d, which is located in the tail section of the aircraft. This gives them the greatest chance of surviving a crash and yielding their recorded data for analysis by experts, such as representatives of the National Transportation Safety Board (NTSB). More recently, large semi-conductor memories have been utilized in the FDR and VDR for storing all the information in order to eliminate moving mechanical parts and increase crash survivability.
Despite the improvements that have been made to the FDR and VDR themselves, it is frequently not possible to recover these devices. This can occur in the case of catastrophic crashes where the tail section is virtually disintegrated, or in the case of crashes at sea in deep water or crashes involving massive rubble. Moreover, even where the FDR and VDR themselves are actually recovered, they often undergo such severe physical damage that critical data cannot be read from these devices. Efforts to determine the precise cause of the crash are thus greatly hampered. Even where the FDR and the VDR can be recovered and the data read therefrom, the recovery and reading process often takes considerable time and effort. This is turn can delay the determination of the cause of the crash and the inspection and repair of key flight safety components on other aircraft, or the implementation of new air traffic control measures.
In order to overcome these deficiencies, it has been proposed to transmit the information collected by the on-board FDR and VDR via radio frequency (RF) data link while the aircraft is in flight. The information is then received by certain ground stations and can be reviewed. For example, U.S. Pat. No. 5,890,079 of Seymour Levine discloses a system that monitors many performance parameters and many aircraft operational parameters, and continuously broadcasts this information along with aircraft identification, audio, video, global positioning and altitude data, to a world wide two-way RF network. Such systems are very large scale and require that massive amounts of many kinds of data be continuously downloaded from all airborne commercial aircraft on a global basis. Besides being impractical from a cost standpoint, many technical problems prevent the deployment of these systems such as channel capacity, frequency spectrum availability, computing power, data conversion to useful format, installation complexity, maintenance, and so forth. To avoid these issues, pre-flight and post-flight downloading of data via direct physical connection, e.g. plugging in a laptop computer, has been proposed, but this completely ignores the loss of data from a crash resulting in an unrecoverable or severely damaged FDR and an unrecoverable VDR.
It is therefore the primary object of the present invention to provide an improved system and method for recording flight data and voice data from an aircraft during flight.
In accordance with one aspect of the present invention a system is provided for recording flight data from an aircraft during flight. An onboard portion of the system is located on an aircraft for monitoring a plurality of flight parameters and detecting a predetermined exceedence indicative of a potential problem. With regard to flight data, predetermined exceedences could include abnormal attitude, control surface actuator failure, low hydraulic fluid pressure, low fuel, near stall speed, excessive engine RPM, engine failure, cabin pressure loss, and so forth. With regard to voice data, predetermined exceedences could include excessive decibel levels, excessive static, overly long periods of silence, and other audible conditions indicative of cockpit intrusion. Flight data representative of the flight parameters is transmitted via RF signals upon the detection of the predetermined exceedence. A remote portion of the system receives the transmitted RF signals carrying the flight data and records the flight data for analysis.
In accordance with another aspect of the present invention a method is provided for recording flight data from an aircraft during flight. A plurality of flight parameters are monitored onboard an aircraft to detect a predetermined exceedence indicative of a potential problem. Upon the detection of the predetermined exceedence, RF signals are transmitted that carry flight data representative of the flight parameters. The transmitted RF signals carrying the flight data are received remote from the aircraft and the flight data is recorded for analysis.